In a scheduling system of data access type according to conventional technology, for each web server, a frequency to update contents on the server is recorded and estimated. Based on the frequency, an interval to acquire the contents is determined. For example, this method is disclosed in JP-A 2009-110196 (Kokai).
However, in case of acquiring facility data from facilities in various buildings by using above method, some facility starts to reply late after receiving a request from a data acquisition side. Accordingly, non-usage time of network increases at the data acquisition side. As a result, usage efficiency of network band falls, and it takes a long time to acquire the facility data from the facilities.